geordabroad

Thanks everyone for the support. Have found alu welder and exhaust is in for patching. Mounting tabs look fine. Will clean exhaust, repack end can, turn out air screw to lean the mix a bit, as well as move to a 70:1 80:1 mix and see how the spark plug reads after a good run. If plug is looking better then I may think about removing both or one of the bottom top gaskets and seeing how the bike carburates. But want to do things in stages so I can tell how each thing affects the bike. Cheers... no doubt you'll hear more from me if I run into further difficulties! Ian

Hi Laser1 you're right to query the .24 inch... it was actually 2.4mm of base gasket. re: the timing... I slotted the holes for the flywheel pickup and moved it anticlockwise. Anyway, you say the engine might be running OK but the mid box could be too hot. What would cause that? all the messing about I've done to calm the bike down with the gaskets below and above the cylinder? If so I might remove a few and see how it behaves. Any advice on how to remove coolant without getting it all over the place? Cheers Ian

Thanks everyone for your replies. I'm not feeling that the engine is running hot, as the fan was kicking on and then off and the plug was oily, pipes sooty etc. I agree with the point about the spacers on the bottom of the cylinder and the retarded timing... I have about 0.24 inch of gaskets and tried a retarded ignition to calm the bike down, but it was running so badly I moved the ignition back to more or less the original position. It still only really pulls smoothly at full open throttle and very low revs, the rest is quite stuttery... but it'as ok for me and means it's pretty calm while i learn to ride it properly. What I'm going to do: 1. I'm contemplating taking 1 or 2 of those spacers out, but I think first I will screw out the mixture screw on the Keihin carb and try and get the bike running without so much oil in the mix... 2. so I'm going to try 1:70 as I have a nice synthetic oil to use. I would like a nice colour on the spark plug 3. I'm looking to see if I can get some aluminium welding done, but as yet, not too much luck. Lots of 'chop shops' for tatty bikes, but I need a specialist welding place. I'm also contemplating buying the mid section new, as it will have new wadding (or whatever you call it) inside, and I'll be in the UK in a couple of weeks, so able to pick it up. I didn't see oil in the mid-section, much more sooty than oily, so I'm not sure whether it was on fire. One theory could be that the mid exhaust section was just slowly failing, and the heat on the side panel etc. was evidence of the aluminium slowly disintegrating... What I'd hate to do is spend money on a new section for it to happen again because there is a cause I have not addressed. Please feel free to comment on my suggestions or offer other advice. By the way, what's the easiest way to take the cylinder head off without spraying coolant everywhere? I have never managed to do this in a controlled way. Cheers Ian

Hello all as usual i'm on the forum as I have a problem. Got my 06 TXT Pro 300 working fine, after calming it down with spacers below the cylinder and a spacer on top, slow action throttle etc. I was finding it a complete handful, as I've never ridden trials before, but with those changes it calmed down a lot. So I've been doing a few hours each weekend in the hills near Beijing. All good except for the following: - spark plug very oily and sometimes means bike stops and needs replacement clean plug. - side panel started smoking and melting next to exhaust - very hot exhaust, but fan wasn't on all the time so engine seemed to be running at OK temperature. then I was out last Saturday and engine noise changed and I realised that I'd blown a hole about an inch across in the middle section of the exhaust on the outside right in the middle where it bends. Directly inbetween the 2 mounting points. It had been so hot that the plastic washer on one of the mounting bolts had melted and some of my gasgas stickers were burning and melting, as was part of the side panel. I've taken the exhaust apart... it's very sooty and where the manifold attaches to the cylinder it's sticky black oily. The frame is coated in soot next to where the hole blew through. So my question is - what would cause this to happen? Is it lowered compression because of the spacers that firstly causes not enough oil to be burnt (I run 50:1) and Secondly, that this causes temperatures on the exhaust to rise? Is it just that my carb is running too rich? Finally, is it possible to weld patches on that middle section of exhaust, or do I need to get a complete new middle section? That's it... any advice gratefully received. Cheers Ian

Last night it was water in the oil... tonight it's a punctured radiator. I tell you. Me and this bike... I just don't think we're meant to be! So, the problem is... the antifreeze is dripping out the radiator near the bottom where the hose pops out. The reason it's leaking is that I took a screw from the side of the top of the radiator to use to hold the little clip that the overflow pipe attaches to ... it slides into a groove on the bottom of the same side of the radiator. Unfortunately, while the screw was fine for the top hole, it punctured the radiator in the bottom hole. Who'd have thought it, eh? so, please, someone, tell me there's an easy fix. I was soooo looking forward to a bit of a razz about this weekend. Thanks Ian

Hello when taking my engine apart it seems some water got into the bottom end of my engine. When I rotate the flywheel there is water on top of the oil as the big end of the piston rotates. I assume I'll have to drain the oil and replace. Any other points I should know before I rebuild top end, put bike back together and do this? Cheers Ian

Thanks copemech. Someone has been in touch who's interested in just what you suggest Cheers, Geordabroad

Thanks Benz would changing to a 250 be easier then? and is a 250 that much different from a 300? Also, as I have a Keihin carb, would changing to the standard delarto help? Ian

Hello, I live in China and it took a lot of work to get my TXT300 Pro shipped over here. At the time it was the only bike I saw that was for sale near my parents house in the UK and fit within the time frame I had to get it shipped. As I am a beginner the more I ride the bike and the more I talk to others the more it becomes blatantly obvious that what I need is a lower capacity bike. My question is (disregarding cost for the moment) is it feasible to replace the 300cc piston and cylinder head with a 200cc piston and head? I have a flywheel weight and a spacer on the top of the cylinder to reduce compression but I think a radical change to 200cc would suit me better. I realise I might also have to change jets in the keihin carb as well. The cost issue... shipping another bike out is out of the question as I'm only likely to be here for another year, and it would be expensive! Any thoughts you might have on whether this is possible and what might be needed, warmly welcomed. Cheers Ian

Hello landed my GasGas 300 pro in a hole and the force was taken by the front end (and my body . On looking at the bike the front wheel now points towards 1 0'clock and the brace holding mudguard on is now bent/ snapped. Bike still rolls ok but it's all skewed. Front wheel is not buckled. Took wheel off, removed forks. Left fork is not smooth when compressing. Right fork seems fine. Can anyone tell me how to check whether both forks are bent? Also, might there be damage to the clamps that hold the forks. They seem fine and there's no obvious damage to the frame. Any ideas on how to fix things or will forks need replacing.? Cheers Ian

Hi just rebuilt my 2006 TXT Pro 300, and went through all the wiring. As you say, the Kokusan diagram does not represent the reality. If you're still having difficulties drop me a line... the diagram's at home and i'm at work, but I might be able to tell you what I found on my bike and that might help. Cheers Ian

Hi everyone I seem to remember there have been posts regarding your Keihin set up, but can't seem to find the one I need. For your information, I have a 300 TXT Pro, flywheel weight, spacer on top of cylinder and slow action throttle. All that has really calmed it down, but since putting the spacer on the cylinder head I haven't managed to get the carb running right. I've got a JJH needle, 125 other jet and have just reduced the 45 jet to a 40 as it was very rich and i'd turned the air/mixture screw to only 1/2 a turn from fully in. The bike pulls ok low down ... struggles and splutters mid way then pulls really well at mid to high revs. So when I'm trail riding between sections or wanting mid revs to roll up through stuff I'm never sure of the engine will splutter or suddenly kick into life once I get past half throttle. I have a GJH needle which I think will help to give a more progressive spread of power (I think Peter B said the JJH was for the 'splat' boys, and I'm definitely not one of them) but I can't imagine it sorting out the poor mid range. Any tips on how to tune my carb? I haven't checked the plug, but it was rich with the 45 jet, and now with the 40 I think it will be a little lean. Any advice appreciated. Cheers Ian

Thanks for the follow up David Yes, in my experience I have found the rider always fails before the bike Best wishes Ian

Thanks for the quick feedback, feet up fun. Was not worried about discolouration, just worried that I might be harming the bike in some way. While I was riding the fan was coming on and then going off so I assumed the temperature of the coolant must be ok. A follow up question: Are there any signs you know of, other than the fan being on all the time, that show the engine is too hot? The reason I ask is that it is relatively cool here at present (20 degrees c) and will be getting much much colder over the next few months (-5 to -15) but I will also ride in the summer when it could be up to 35 or 40 degrees c each time I come out. How can I tell if the engine is seriously overheating? Cheers Ian in Beijing

Hello just rebuilt my 06 TXT Pro 300 after new kickstart gears, new piston and rings and new jets in the carb. Also put a spacer on the top of the cylinder to reduce compression to calm it dwn a bit. Got it going after leaning the carb quite a bit (turned the air screw in 1.5 turns) as the plug was really oily initially. Now there doesn't seem to be any problems, however at the end of the ride yesterday I noticed that the front bend of the exhaust, just after it exits the cylinder, had turned a yellow/ gold colour. Is this nornmal or does it hint at the engine running too hot or some other hidden problem? In addition I did notice, when I stopped half way through the ride yesterday, that there was smoke coming out the exhaust, as well as coming off the side plastics that had melted against the exhaust. Is smoke from the end of the exhaust normal after a rebuild with new piston and a little Blue Hylomar to keep the head spacer in place? Cheers Ian